Zooming into an Atom

Animation Credit: T. Pyle, Caltech/MIT/LIGO Lab

On September 14, 2015, LIGO became the first instrument to detect gravitational waves on Earth. When two black holes, each about 30 times more massive than our sun merged, they generated gravitational waves—ripples in space and time. More than a billion years later, those waves reached LIGO's detectors, causing the distance between its mirrors—separated by 4 kilometers—to change by roughly 1/1000th the diameter of a proton. This animation zooms in on the proton of a hydrogen atom. The movement of the proton shows the tiny changes measured by LIGO.